What'’s Safe, What Isn't

When you're pregnant, you are your baby's sole source of oxygen, nutrients and—when you take medicine—drugs. You wouldn't take a prescription drug without your doctor's approval, but many women pop over-the-counter (OTC) pills without a second thought. "Women think these must be safer than prescription drugs," says Donald L. Sullivan, R.Ph., Ph.D., who teaches pharmacy practice at Ohio Northern University in Ada. "But they are potent pharmacological agents."

Of course, this doesn't mean that you have to swear off all medications for nine months. In fact, in certain situations, undermedicating could make you even sicker—and potentially harm your baby. "Severe diarrhea and nausea are good examples," says Isabelle Wilkins, M.D., director of maternal-fetal medicine at Baylor College of Medicine in Houston. "If you don't treat these problems, you may not be getting enough nourishment for your baby."

Because drug studies aren't performed on pregnant women, most of the data on the effects of OTC medicines during pregnancy come from animal studies, which are of limited help. Why? "Animal placentas are very different from human placentas," says Rebecca Shiffman, M.D., director of obstetrics at New York Methodist Hospital in Brooklyn.

Tracing back birth defects> Since so few drug studies have been done during pregnancy, when a birth defect does occur, doctors try to figure out what the woman was exposed to while pregnant, says Sullivan, who wrote The Expectant Mother's Guide to Prescription and Nonprescription Drugs, Vitamins, Home Remedies and Herbal Products (Griffin Trade Paperback, 2001). But rarely is a cause-and-effect relationship between any one drug and a specific defect identified.

Sometimes it's the absence of a link that proves significant. "Once in a while, we get reports that something is likely to be safe because millions of [pregnant] women have used it without problems," Wilkins says.

That said, the only three over-the-counter drugs that the experts interviewed here agree are generally considered safe to use during pregnancy are acetaminophen (Tylenol), diphenhydramine (Benadryl) and calcium carbonate (Tums). But they advise exercising caution even with these remedies during the first trimester, when the baby's organs and systems are forming.

Your doctor can best determine whether taking a given medication during pregnancy is worth any potential danger. With that in mind, the chart on pg. 60 offers nonmedical remedies for common pregnancy complaints, as well as the current thinking on some popular OTC medications.